渗吸是页岩油藏压裂开发的重要机理,最大渗吸动用距离是渗吸动用范围评价的直接指标,对页岩油藏开发具有重要意义。为确定页岩油藏最大渗吸动用距离,在表征页岩油藏毛细管力曲线基础上,运用渗流理论、数值计算方法,建立了页岩油藏逆向渗吸最大渗吸动用距离计算方法,通过与室内实验结果进行对比,验证了计算方法的可靠性,同时开展了最大渗吸动用距离影响因素分析。研究表明:随着渗透率增加,最大渗吸动用距离呈线性增加,但达到最大渗吸动用距离所用时间呈指数降低;油水黏度比对最大渗吸动用距离无影响,但原油黏度越大,达到最大渗吸动用距离所需时间越长;当储层渗透率为0.05 mD、接触角为45 °、界面张力为50 mN/m时,最大渗吸动用距离为2.2 m,所需时间为170 d,用时较长。该研究可为页岩油藏渗吸动用范围评价提供借鉴。
Imbibition is an important mechanism for fracturing development in shale reservoirs,and the maximum imbibition distance is a direct indicator for evaluating the scope of imbibition,which is of great significance for the development of shale reservoirs.In order to determine the maximum imbibition distance of shale reservoirs,a calculation method of imbibition distance of countercurrent imbibition in shale reservoirs was developed according to the principles of filtration theory and numerical methods and based on the characterization of the capillary curve of shale reservoirs.The results were compared to the results of laboratory experiments so as to verify the reliability of the calculation method and analyze the influencing factors of the maximum imbibition distance.The research shows that the maximum imbibition distance increases linearly with the increase of permeability,but the time required to reach the maximum imbibition distance decreases exponentially;the ratio of oil/water viscosity has no effect on the maximum imbibition distance,however,the greater the viscosity of crude oil,the longer the time required to reach the maximum imbibition distance;when the reservoir permeability is 0.05 mD,with the contact angle of 45 ° and the interfacial tension of 50 mN/m,the maximum imbibition distance is 2.2 m,taking 170 d,which takes longer time.This study provides reference for evaluating the range of imbibition distance in shale reservoirs.
[1] 谷潇雨,蒲春生,黄海,等.渗透率对致密砂岩储集层渗吸采油的微观影响机制[J].石油勘探与开发,2017,44(6):948-954.
GU Xiaoyu,PU Chunsheng,HUANG Hai,et al.Micro-influencing mechanism of permeability on spontaneous imbibition recovery for tight sandstone reservoirs[J].Petroleum Exploration and Development,2017,44(6):948-954.
[2] 吴润桐,杨胜来,谢建勇,等.致密油气储层基质岩心静态渗吸实验及机理[J].油气地质与采收率,2017,24(3):98-104.
WU Runtong,YANG Shenglai,XIE Jianyong,et al.Experiment and mechanism of spontaneous imbibition of matrix core in tight oil-gas reservoirs[J].Petroleum Geology and Recovery Efficiency,2017,24(3):98-104.
[3] 黄睿哲,姜振学,高之业,等.页岩储层组构特征对自发渗吸的影响[J].油气地质与采收率,2017,24(1):111-115.
HUANG Ruizhe,JIANG Zhenxue,GAO Zhiye,et al.Effect of composition and structural characteristics on spontaneous imbibition of shale reservoir[J].Petroleum Geology and Recovery Efficiency,2017,24(1):111-115.
[4] 韦青,李治平,王香增,等.裂缝性致密砂岩储层渗吸机理及影响因素——以鄂尔多斯盆地吴起地区长8储层为例[J].油气地质与采收率,2016,23(4):102-107.
WEI Qing,LI Zhiping,WANG Xiangzeng,et al.Mechanism and influence factors of imbibition in fractured tight sandstone reservoir: an example from Chang 8 Reservoir of Wuqi Area in Ordos Basin[J].Petroleum Geology and Recovery Efficiency,2016,23(4):102-107.
[5] 黄兴,窦亮彬,左雄娣,等.致密油藏裂缝动态渗吸排驱规律[J].石油学报,2021,42(7):924-935.
HUANG Xing,DOU Liangbin,ZUO Xiongdi,et al.Dynamic imbibition and drainage laws of factures in tight reservoirs[J].Acta Petrolei Sinica,2021,42(7):924-935.
[6] WANG Xiangzeng,PENG Xiaolong,ZHANG Shoujiang,et al.Characteristics of oil distributions in forced and spontaneous imbibition of tight oil reservoir[J].Fuel,2018,224:280-288.
[7] DOU Liangbin,YANG Min,GAO Hui,et al.Characterization of the dynamic imbibition displacement mechanism in tight sandstone reservoirs using the NMR technique[J].Geofluids,2020,2020:8880545.
[8] 杨正明,刘学伟,李海波,等.致密储集层渗吸影响因素分析与渗吸作用效果评价[J].石油勘探与开发,2019,46(4):739-745.
YANG Zhengming,LIU Xuewei,LI Haibo,et al.Analysis on the influencing factors of imbibition and the effect evaluation of imbibition in tight reservoirs[J].Petroleum Exploration and Development,2019,46(4):739-745.
[9] 王秀宇,巨明霜,杨文胜,等.致密油藏动态渗吸排驱规律与机理[J].油气地质与采收率,2019,26(3):92-98.
WANG Xiuyu,JU Mingshuang,YANG Wensheng,et al.Dynamic imbibition principles and mechanism of tight oil reservoirs[J].Petroleum Geology and Recovery Efficiency,2019,26(3):92-98.
[10] WANG Zhiyuan,YANG Zhengming,DING Yuanhong, et al. A generalized capillary imbibition model for porous media in tight reservoirs[J].Advances in Civil Engineering,2018,2018:4148734.
[11] WANG Fuyong,ZHAO Jiuyu.A mathematical model for co-current spontaneous water imbibition into oil-saturated tight sandstone:upscaling from pore-scale to core-scale with fractal approach[J]. Journal of Petroleum Science and Engineering,2019,178:376-388.
[12] WU Zhongwei,CUI Chuanzhi,YE Yinzhu, et al.A fractal model for quantitative evaluating the effects of spontaneous imbibition and displacement on the recovery of tight reservoirs[J]. Journal of Petroleum Science and Engineering,2021,198:108120.
[13] LI Shuai,DING Yunhong,Cai Bo,et al.Solution for counter-current imbibition of 1D immiscible two-phase flow in tight oil reservoir[J].Journal of Petroleum Exploration and Production Technology,2017,7(4):727-733.
[14] 杨柳,赵逸清,蒋荣敏,等.致密油储层毛细管力自发渗吸模型分析[J].力学与实践,2019,41(4):398-404.
YANG Liu,ZHAO Yiqing,JIANG Rongmin,et al.Spontaneous capillary imbibition model in tight oil reservoirs[J].Mechanics in Engineering,2019,41(4):398-404.
[15] 李爱芬,刘敏,张化强,等.低渗透油藏油水两相启动压力梯度变化规律研究[J].西安石油大学学报(自然科学版),2010,25(6):47-50.
LI Aifen,LIU Min,ZHANG Huaqiang,et al.Study on the change law of oil-water two-phase start-up pressure gradient in low permeability reservoir[J].Journal of Xi'an Shiyou University(Natural Science Edition),2010,25(6):47-50.
[16] 李爱芬.油藏物理学[M].东营:中国石油大学出版社,2011:256-258.
LI Aifen.Reservoir Physics[M].Dongying:China University of Petroleum Press,2011:256-258.
[17] LI Kewen,HORNE R.Comparison of methods to calculate relative permeability from capillary pressure in consolidated water-wet porous media[J].Water Resources Research,2006,42:W06405.
[18] GE Hongkui,YANG Liu,SHEN Yinghao,et al.Experimental investigation of shale imbibition capacity and the factors influencing loss of hydraulic fracturing fluids[J].Petroleum Science,2015,12:636-650.